With the introduction of West Nile virus into the United States and the continuing presence of malaria, dengue, encephalitis viruses, and leishmania in much of the world, insect monitoring and control of vector-borne diseases is a critical healthcare need. Presently, there are approximately 550 State health departments and mosquito abatement districts throughout the United States that spend approximately 400 million dollars annually on mosquito control. Additionally, insects cause enormous agricultural damage worldwide either directly or indirectly through disease transmission.
Traps to attract insects are commonly used for surveillance and control of insect-vectored diseases or for public health research. Universal black light traps are used by the United States Department of Agriculture to monitor crop pests in fields and storage areas. Centers for Disease Control (CDC) light traps are used routinely to monitor insect populations and disease prevalence. The military uses light traps to monitor insects in and near troop encampments. In Iraq and Afghanistan, a large number of cases of leishmaniasis among U.S. troops has increased the need for effective surveillance of phlebotomine sand flies, the insect vector of leishmaniasis. Researchers interested in disease vectors (flies, mosquitoes, sand flies, and other insects and arthropods) also use light traps for collecting and monitoring.
In general, ultraviolet (UV) light traps attract more insects than similar white light traps, but power consumption is much greater for UV traps and is often a limiting factor. Further, the collection of non-target insects and arthropods in either type of trap can complicate results and analyses. Adequate public health surveillance is often impossible because of the high costs and logistical problems associated with using current CDC-traps or comparable light traps. Other limitations of known capture traps include an inability to readily adjust to different conditions or environments, irregularly shaped areas, and to target specific insects or arthropods.
A number of attempts to improve upon white light traps have used incandescent lights, fluorescent lights, or light emitting diodes (LEDs) alone or in combination, as attractants. Other insect traps use bait such as CO2 or heat, either alone or in combination with each other or light. For example, U.S. Pat. No. 7,191,560 to Harris uses heat and light; U.S. Pat. No. 7,281,350 to Wilbanks uses a plurality of green LEDs; U.S. Pat. Nos. 7,181,885 and 6,662,489 to Spiro use blue light, preferably from at least one LED, in combination with heat, carbon dioxide, and moisture; U.S. Pat. No. 7,073,287 to Lau uses an LED emitting low intensity violet light; and U.S. Pat. No. 6,965,205 to Piepgras refers to the use of LEDs as an insect attractant and repellent.
U.S. Pat. No. 6,840,003 to Moore utilizes a combination of different forms of light from LED, ultraviolet, and fluorescent light sources and discloses that a plurality of light sources will effectuate greater trapping efficiency, but Moore teaches away from selectively using such light sources to target specific arthropods. In fact, the invention of Moore is specifically designed to attract and trap all types of insects in an area without specificity. Similar to Moore, U.S. Pat. No. 6,199,316 to Coventry utilizes a combination of ultraviolet and broad spectrum light with a light mixer, such as a prism, to produce a light attractive to a wide range of target insects. The spectrum light of Coventry is specially designed to provide a wide range of different wavelengths simultaneously.
Importantly, none of these examples provide for or teach a means of selective trapping that is crucial for reliable surveillance and pest control without damage to non-target, beneficial species.
U.S. Patent Appl. Pub. Nos. 2007/0068068 of Weiss and 2007/0056208 of Chen both teach light traps designed to specifically target mosquitoes by using a variety of light sources to produce wavelengths in the UV and visible spectra. Weiss also teaches that flickering or operating LEDs in sequence may be a useful attractant and that specific wavelengths of either the UV or visible spectrum may be used. While Weiss states that different species of mosquitoes are attracted to different wavelengths of light, Weiss does not identify those species or their respective attractant spectra. Further, neither Weiss nor any other known patent or application disclose or teach using light emitted from LEDs without a reflector or light mixer of some type. Using a reflector reduces the field of insect capture by creating blind spots behind the reflectors.
Presently, the art does not provide or teach traps that can be adjusted or programmed to selectively target a species or group of arthropods in one set of circumstances and then be adjusted to selectively target a different species or group of arthropods in another set of circumstances. It is desired that a means of easily adjusting existing non-selective traps to selectively trap targeted arthropods and simultaneously be less attractive to non-targeted arthropods be found. Further, it is desired that such methods and compositions be economical and sufficiently flexible to adjust to numerous different types of conditions. It is desired that a light trap be more energy efficient and selective under field conditions so that costs are lowered and monitoring, especially of disease-vectors or crop pests, is more sensitive and reliable.